Double-acting spring for pin drive and clutch drive counterbores



5 s. A. GVETTS 2,801,860

- DOUBLE-ACTING SPRING FOR PIN DRIVE AND CLUTCH DRVIVE CQUNTERBORES IFiled Oct. :50, 1956 J orhemf- United States Patent ouana-aernseisrnnsFOR rTINDRtv N CLUTCH DRIVE COUNTERBORES Sidney A;Gotta-"Rb ckforifl,Illt,ass'ignor-to Metal Cutting Tools, Inc, Rockford, Ill., acorporationof lllinois Application Oc'tdberfil), 1 956, Serial-No. 619,305

-'9'-Ciinis. (G1. 279- 97) The present invention relates to-adouble-acting spring "forlpin 'driveandclutch drive counterbores forretaining the cutterby the fiat portion on the-shankthereof, withintheholder hereinafter described and claimed.

Thea-principal objectof this-invention is to provide a spring means forsecurely looking a cutting tool in the socket of t the toolholder-againstaccidental release either 1 type, acon'struction which isexpensive and whichcannot be -'depended upon under conditions of 1 use.

Other obj'ects will appear hereinafter throughout the specification.

In the drawings:

Figure 1 is a longitudinal vertical sectional view through a boring tooland its holding socket, with parts in elevation;

Figure 2 is a transverse vertical section taken on the line 2-2 ofFigure 1;

Figure 3 is a transverse vertical section taken on the line 3-3 ofFigure 1;

Figure 4 is a transverse vertical section taken on the line 4-4 ofFigure 1;

Figure 5 is an exploded view of the tool holder and tool, together withthe spring and pin for holding with the latter within the former; and

Figure 6 is the spring blank from which the doubleacting spring isformed.

The present invention comprises a double-action spring of generalcircular configuration having inturned ends, having an ear which is benton a ditferent radius from other portions of the spring. This ear actsas a tension spring on the fiat portion of the cutter, and when engagedtherewith prevents the cutter from dropping out of the holder before itis engaged by the pin. The main or circular portion of the spring actsas a friction drag against the circular recessed walls of the holder,and this spring is so constructed that it turns more freely in aclockwise direction than it does in a counter-clockwise direction. Asthe cutter is turned clockwise on the pin, such turning also rotates andmaintains a pressure against a flat portion of the cutter, therebyholding the cutter within the holder. The construction is such thatgreater pressure is required to remove the cutter from the holder thanis necessary to engage the cutter with the holder.

Referring to the drawings, the numeral 10 indicates the tool or drivenmember, the same being provided with a circular shank 12 having a flator key portion 14 thereon including a bayonet groove, the key portionand bayonet groove forming a key means. As shown in Figure 1, the drillor driving member, tool holder 16 has a longitudinal cylindrical recess18 for the reception of the shank 12, it being noted that the entirerecess is not occupied by the 2,801,860 "Fatented Aug. 6, 1957 2. .pin,there being a cylindrical space 20 when the pin is in fpla'ce on theholders The holder 16 is .provided with theusual transverse passagewayor'keyway l z for the reception of thelpin or key 24 which engages thebayonet groove 37 whereby to (prevent relative rotation between thedrill and the drill holder when the parts arein theposition shownlinFigure 4.

, Mounted within :the space 20 is the double-acting spring 26, thisbeing formed from the blank shown in Figure 6.

The spring blank shownin Figure .6 is "formed into a C-shaped form, assh'own in the other figures, the natural tendency of the spring being toexpand and thereby frictionally engage the walls of the longitudinalcylindrical recess 18. This frictionalengagement will prevent the springfrom falling out of the recess. This spring is pro vided withconfronting end portions 28 and 30, each having an aperture and 34 forthe reception of a suitable "tool for removing the spring from therecess18.

The spring is .provided adjacent confronting end portion 28 with anextension or car 36. This: ear is bent .on a different angle from theconfronting end portions whereby it :will .bear against the Hat portion14 of the cutter. The ear 3fi has a spring action of its own totherebyfrictionally engagethe said flatport-ion. iItthuspreverits-theputterfrom dropping out of the holder 16 before the pin24 has been fixed in position in passageway 22, as shown in Figure :4.

harder the spring 26 is "first positioned within the recess 18 by meansof a suitable tool, not shown, which will contract the cylindricalsurface of the spring so as to permit its insertion within the saidrecess, as shown in Figure l. The tool shank 12 is next inserted withinthe recess, following flat portion 14 positioned under pin 24, the flatportion 14 engaging the car 36, as shown in Figure 3. The clockwiserotation is started, the parts being relatively rotated until bayonetgroove 37 is engaged with the pin 24. As previously stated, the circularor main portion of the spring acts as a friction drag against the innerwalls of the holder. When it is desired to remove the tool from theholder, these operations are reversed.

It will be noted that during all of the time the tool is within theholder the ear 36, due to the fact that it is biased toward the flatportion 14, frictionally engages this portion and thereby prevents thetool shank from moving out of the holder recess. It will be noted thatthe spring 26 and its ear 36 provide a double action spring effect, thecircular portion frictionally engaging the internal walls of the recess18 while the ear 36 frictionally engages the fiat portion 14 of thetool, both being biased spring actions.

It will be obvious to those skilled in the art that variousmodifications may be made in the invention without departing from thespirit and scope of the appended claims.

What is claimed is:

1. In a coupling comprising a driving member having a longitudinalrecess and a transverse key passageway, a driven member having a shankextending into the longitudinal recess of said driving member, saidshank having a key means thereon, a key extending through saidtransverse passageway and engaging said key means of said driven member,and circular spring means having a portion frictionally engaging thewalls of said longitudinal recess, said spring member having an earfrictionally eninto the longitudinal cylindrical recess of said drivingmember, said shank having a key means thereon, a key extending throughsaid transverse passageway and engaging said key means of said drivenmember, and circular spring means having a portion frictionally engagingthe walls of said longitudinal recess, said spring member having an earfrictionally engaging the key means of said driven member.

3. In a coupling comprising a driving member having a longitudinalrecess and a transverse key passageway, a driven member having a shankextending into the longitudinal recess of said driving member, saidshank having a key means comprising a flat portion and a bayonet groovethereon, a key extending through said transverse passageway and engagingsaid bayonet groove of said driven member, and circular spring meanshaving a portion frictionally engaging the walls of said longitudinalrecess, said spring member having an ear frictionally engaging the flatportion of said key means.

4. In a coupling comprising a driving member having a longitudinalcylindrical recess and a transverse key passageway, a driven memberhaving a shank extending into the longitudinal cylindrical recess ofsaid driving member, said shank having a key means comprising a fiatportion and a bayonet groove thereon, a key extending through saidtransverse passageway and engaging said bayonet groove of said drivenmember, and circular spring means having a portion frictionally engagingthe walls of said longitudinal recess, said spring member having an earfrictionally engaging the flat portion of said key means.

5. In a drill assembly comprising a holder having a longitudinal recessand a transverse key passageway, a driven member having a shankextending into the longitudinal recess of said driving member, saidshank having a key means thereon, a key extending through saidtransverse passageway and engaging said key means of said driven member,and circular spring means having a portion frictionally engaging thewalls of said longitudinal recess, said spring member having an earfrictionally engaging the key means of said driven member, a tool having a shank adapted to said recess, said shank having a flat portion,and said holder having a key adapted to engage said fiat portion, saidspring means further including a C-shaped spring member, said springmember being biased to engage the walls of said longitudinal recess.

6. The structure of claim 5 wherein said C-shaped spring member hasconfronting end portions.

7. The structure of claim 5 wherein said C-shaped spring member hasconfronting end portions and a flat portion.

8. The structure of claim 5 wherein said Cshaped spring member isprovided with confronting end portions, said end portions havingperforations for the reception of a tool whereby to insert and removesaid spring from said longitudinal recess.

9. The structure of claim 5 wherein said C-shaped spring member isprovided with confronting end portions, said end portions havingperforations for the reception of a tool whereby to insert and removesaid spring from said longitudinal recess, said spring member having aflat portion.

References Cited in the file of this patent UNITED STATES PATENTS1,525,471 Stevens Feb. 10, 1925 1,701,631 Slater Feb. 12, 1929 1,757,444Stevens May 6, 1930 2,512,149 Gartin June 20, 1950

